The severity of stress concentration under cyclic fatigue loads is higher in__________________?
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Answer: A. ductile materials
Explanation
Ductile materials exhibit higher notch sensitivity under cyclic fatigue loading conditions. Stress concentration factors create severe localized plastic strain at notches in ductile metals. This high sensitivity significantly accelerates fatigue crack initiation and subsequent structural failure. Stress concentrations occur around geometrical discontinuities like holes fillets or sharp machining notches. Cyclic fatigue loads subject components to repeated fluctuating stresses over millions of operating cycles. Notch sensitivity quantifies how susceptible a material is to theoretical stress concentration effects.
Machine components subjected to rotating bending loads require careful fillet radius design considerations. Automotive crankshafts and aircraft spars must minimize stress concentrations to prevent catastrophic fatigue failures. Engineers apply stress relief features to improve the fatigue life of ductile metallic structures. Brittle materials already contain numerous internal microscopic flaws reducing their relative notch sensitivity. Stress concentration severity clearly differs between materials based on their specific microscopic structures. Predictable analytical models exist for evaluating cyclic fatigue behavior across various engineering materials.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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